Griesser



March 3, 1964 F. GRIESSER 3,123,131

ROLLERSHUTTER- Filed Oct. 25, 1958 2 Sheets-Shet 1 INVENTOR:

B WMKWQ w (mi March 3, 1964 F. GRIESSER ROLLER-SHUTTER 2 Sheets-Sheet 2 Filed Oct. 23, 1958 INVENTOR: ma GRIESSER [Z i A By: W

United States Patent 3,123,131 ROLLER-SHUTTER Fritz Griesser, Aadorf, Switzerland, assignor to Griesser A.G., Aadorf, Switzerland Filed Oct. 23, 1958, Ser. No. 769,162 1 Claim. (Cl. 169-232) The invention consists in the provision of a roller shutter having slats formed of strips of sheet material which is bent to provide hollow slats having substantially flat sides, a roof-shaped top and a longitudinal groove along the bottom for cooperation with the roof-shaped top of the next lower slat, the longitudinal edge portion of said strips being bent and folded to interlock at the bottom of the slat, and slits being provided at the top and bottom portions of the slats for the passage of slat carrying tapes having projections for supporting the slats at the desired vertical spacing.

The method according to the invention for producing the roller shutter comprises the steps of first lacquering a plane strip of sheet material, subsequently imparting to said strip a continuously extending longitudinal profile by means of profiling rollers and cutting pairs of transversely fligned slits in the strip, transversely folding the profiled strip to form a fiat tube having an upper roof-shaped portion, joining the two longitudinal edge portions of the strip by a folding operation, cutting from the finished tube slats of desired length and inserting carrier tapes through said slits in the tube.

The production of the hollow slats by shaping a continuous sheet material strip by means of profiling rollers in a single operation respresents a substantial improvement with respect to the rate of production in comparison with the conventional pressing and bending of the individual slats. On the other hand, the lacquering operation preceding the step of profiling offers the advantage of enabling the uniform lacquering of a smooth metal band in convenient manner, preferably also in a continuous operation.

The present invention will now be described more fully with reference to the accompanying drawings illustrating, by way of example, several embodiments of the invention, and in which:

FIG. 1 is a perspective sectional view of a portion of a roller shutter according to the invention,

FIG. 2 is an elevation of a carrier tape of the roller shutter according to FIGURE 1,

FIGS. 3 and 4 are views similar to FIGURES 1 and 2 of a modification,

FIG. 5 is a fragmentary vertical section of a third example,

FIG. 6 shows a perspective view of a portion of a carrier tape of the example according to FIG. 5, and

FIGS. 7 and 8 are views similar to FIGURES 5 and 6 of a fourth example.

- The roller shutter shown in FIGS. 1 and 2 comprises hollow metal slats 1 which are provided with a roofshaped top portion 1a and a channel-shaped bottom portion 1b. Provided in the top and bottom portions in, 1b of each slat 1 are slots 2 through which pass metal foil carrier tapes 3. Equidistantly punched semicircular tongues 4 are provided in the middle of the length of the tape 3. The tongues 4 are uniformly bent outwards from the plane of the tape under an acute angle. As shown in 3,123,1315 Patented Mar 3, 1964 FIG. 1, each slat 1 is supported with its channel-shaped bottom portion upon one of the tongues 4 of a carrier tape 3, the mutual distance of the tongues 4 being approximately equal to the height of the slats 1. The tongues 4 not only serve for the purpose of supporting the slats 1, but they also hold said slats a desired distance apart from each other. This distance of the slat 1 is selected so that the upper roof-shaped edge portion of a slat engages with clearance into the lower channel-shaped edge portion of the next following upper slat in such a manner that from no side of the roller shutter light can directly pass through the small gap left between the slats, but air is permitted to pass through the gaps.

In producing the slats 1 of the roller shutter shown in the drawings, I proceed as follows:

A plane continuous metal strip is first lacquered on one of its faces in a continuous operation and subsequently, if required, passed through a drying chamber. The strip prepared in such a manner is then passed between suitable profiling rollers. During this first rolling operation, the bottom portion 1b with the end flange 1c are formed and bent out of the plane of the strip; also the stiffening channel 1e is formed and the edge portion 1d partly folded over. The slits 2 are also formed during this first rolling operation by cutting pairs of transversely aligned slits in the strip at the required longitudinally spaced places where the carrier tapes 3 are to be passed through the finished slats. Thereafter, folding of the profiled strip along a longitudinal line passing through one of the series of slits and forming the upper edge of the slat is effected by additional roller tools. In this operation the free edge portions 10 and id of the strip are bent towards each other and hooked into each other so that the edge portion of one of the lateral walls, which forms the recessed bottom portion of the slat is urged with its terminal flange 1c against the other lateral wall by the terminal flange 1d of this wall. During this operation, the flanges 1c, "1d and the wall portion on which the flange 1d is formed are firmly pressed together to form a tight connection, thus providing a completely closed hollow profile from which individual lengths may then be successively severed to obtain the hollow slats. The hollow slats thus produced are completely finished and do not require any subsequent machining operation.

Alternatively, the slits 2 can be cut into the metal strip already before lacquering it, or the slats can be completely finished and cut into the desired lengths, and only then the slits 2 can be cut into the top and bottom portions of the slats.

The described process of slat production is particularly advantageous owing to the operational steps adapted for continuous application and due to the uniform layer of lacquer already produced on the plane metal band.

The roller shutter shown in FIGS. 3 and 4, which otherwise is built similar to the one shown in FIGS. 1 and 2, has the semicircular tongues 4 of the carrier tapes provided with a middle rib 4a on their upper side. The height of the gaps between the slats 1 is somewhat enlarged by means of these ribs 4a- In placing the slats 1 in proper position on the carrier tapes 3, the slats are moved over the resilient tongues 4 until they are caught between their associated pairs of tongues. Owing to the weight exerted by the slat 1 situated above a tongue, the tongues 4 abut against the 3 roof-shaped edge portion la of the next following lower slat so that the tongues cannot be bent back into the plane of the tape. The slats 1 thus are perfectly fixed on the carrier tapes 3 and spaced the proper distance apart from each other, in spite of the fact that they are only loosely strung on these tapes.

It is understood that in place of semicircular tongues also differently shaped tongues for instance of triangular or rectangular form could be punched out of the carrier tapes 3, in order to fix the slats.

The roller shutter shown in FIGS. 5 and 6 comprises hollow metal slats 11 which are provided with a roofshaped upper edge portion 11a and a channel-shaped lower edge portion lib. Metal carrier tapes 13 pass through slits 12 which are provided in the two edge portions 11a, 11b of each slat 11. In the middle of the length of the tapes 13 sheet metal strips 14 equidistantly spaced from each other are attached, e.g., by means of spot welding. A protrusion, acting as spacing means for the slats 1i strung on the carrier tapes 13, is provided on each strip 14. For this purpose two laterally spaced slits are provided in the strip 14 and extend in longitudinal direction of the carrier tape 13. The two outer strip portions 15a, each of them inwardly bounded by one of said two slits, are domed away from the carrier tape to project outwards of the plane of the strip in semicylindrical shape, while the strip portion 15b located between the two longitudinal slits is also outwardly domed away from the plane of the strip in semicylindrical shape in a direction opposite to the portions 153a through a corresponding rectangular opening 16 (FIG. 6) of the carrier ta e 13. Three domed strip portions thus form rigid projections upon which the slats 1.1 of roller shutter can rest their bottom portions lib.

instead of forming three projections by three domed stri parts, as shown in the example according to FIGS. 5 and 6, each strip 14 could be provided only with a single slit located in the middle of the strip, the strip portions situated on both sides of this slit then being domed towards opposite sides of the strip, in order to form two projections. Instead of outwardly doming the strip portions located laterally of the longitudinal slit or slits in semicylindrical manner, these strip portions could also be outwardly bent for instance prismatically or in a shape showing triangular cross-section. Though the strips 14- shown in FIGS. 5 and 6 are narrower than the carrier tape 13, strips and carrier tape could also be of equal width.

The roller shutter shown in FIG. 7 comprises hollow slats 29 which, except a few details, are formed in similar manner as the hollow slats 1 and 11 of the previously described examples. An essential structural difference is represented by the wider slot 21 provided in the bottom portoin of the hollow slat; this enlarged slot is due to the formation of the carrier tapes which differ from the construction employed in the preceding examples. In this case the carrier tapes are built up of separate members. According to FIG. 8 the individual members 11% are made from flexible band material and at one end they are provided with a rectangular perforation 13 while the other end of each member is provided with two transversely extending lobes 17. These lobes are punched out of the band material forming said members and bent out of the plane of the member for approximately the thickness of the band material so as to extend parallel to the plane of the member and to symmetrically project towards either side from the middle zone of the end of the member in lateral direction.

It is evident from FIG. 8 that the two transverse lobes 17 at the bottom end of each member 116 with their twice bent-oil portions pass through the perforation 18 at the top end of the adjacent member lit) and abut with their inner face against the band material of this latter member. The root portions of th lobes 17 thus are guided within the elongate slots 18 and can efiect a limited movement in the longitudinal direction of the carrier tape in such a manner that each two successive members may be moved towards each other from their drawn-apart position, indicated in FIG. 8, and moved 5 until the root portions of the lobes contact the inner end of the perforation 18. In this manner there is obtained the shortening required for closing the roller shutter with the slats overlying in light-proof arrangement, or the lengthening of the carrier bands necessary for drawing the slats away from each other.

The members 11%, adapted for building a roller-shutter from the slats 20, are provided with three abutments 180 and 190, which act on both sides of the members. All abutments are formed as resilient flaps which are punched out from the band material of the members and bent in outward direction. The two upper abutments 1% are outwardly bent towards one side of the tape, while the lower abutment 189 is outwardly bent towards the other side of the tape.

the members lltl are passed through the slots 21 and 22 of the hollow slats from the bottom end thereof, whereby the abutments 19% while slipping through the slots 22 are resiliently depressed, but spring back to their efltective position after having passed the slot 22. The hollow slats 2% are held on the carrier bands by the abutments 180. The abutments 190 engage the roof edges and prevent the carrier band from slipping downwards.

Instead of providing punched-out flaps, the abutments 180 and 1% could also be formed as extensions, in which case the elasticity of the material used for the hollow slats would permit the upper extrusions to pass through the slots 22. The lobes 17 could also be modified by providing for instance a crossweb in place of each of the two lobes or else by employing only one lobe. For limiting the lateral relative movements of the members the said single lobe could in addition also be combined with an extrusion in place of the crossweb of the second lobe.

Moreover, it would also be feasible to directly employ a the lobes 17 as abutments for the slats.

Notwithstanding their extraordinarily great mobility, fiexibilty and easy rolling movement, the roller shutters according to the invention excel by particular sturdiness and durability. Last but not least, this advantage results from the fact that very small slots in the hollow slats suifice for the reception of the carrier tapes or tape members, and any substantial weakening of the slat structure thus is avoided.

The hollow slats of all previously described roller shutters are produced in the same way, i.e., the band used for making the hollow slats first is lacquered, subsequently profiled, then hooked together with its longitudinal edges and finally, after providing the necessary slits, strung up on the carrier tapes.

I claim:

In a roller shutter, the combination of a plurality of hollow slats of sheet material, flexible carrier tapes on which said slats are suspended, said slats each having a top portion which in cross section has an upwardly convex wedge shaped c-ross section wtih two oppositely inclined wall portions, and an upwardly concave bottom portion having in cross section a substantially horizontal middle surface portion and sharply downwardly inclined end portions connecting the bottom portion to the side walls of the hollow slat, the top portion of the next lower slat projecting toward the space within the concave bottom portion of each slat, the slats each being formed by a strip of sheet material bent to a tube, the longitudinal edges of said strip being united at said bottom portion of the slat, the apex of said top portion and the horizontal middle surface of the bottom portion having slits formed therein, and the flexible carrier tapes passing through said slits, said carrier tapes having longitudinally spaced pro-.

jections thereon between each pair of slats and projecting The assembly of the roller shutter is effected in that said top portion of the slats and retaining said slats in substantially vertical positions on said tapes, each of said projections on said carrier tapes being strips of rigid material bent into semicircular form, there being two semicircular pro'ections extending in one direction from the tape and one semicircular projection extending in the other direction from the tape, said semicircular projections engaging the substantially horizontal middle portion and one of the sharply downwardly inclined end portions of the bottom portion of the upper slat in a pair of slats, and engaging the top portion of the lower slat in a pair of slats at the apex of the oppositely inclined walls.

References ited in the file of this patent UNITED STATES PATENTS Lampart Mar. 8, 1932 Calton Aug. 30, 1949 FOREIGN PATENTS Germany Aug. 3, 1908 Germany Oct. 20, 1908 Germany Dec. 1, 1908 Italy Sept. 1, 1951 Italy Sept. 19, 1951 France Mar. 11, 1957 

